JPH11247707A - Crank angle detecting device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crank angle detecting device not to be affected by the error in manufacture. SOLUTION: Teeth from 1 to 34 of a rotor 200 are arranged at the target distance 10 deg. (target angle is 30 deg. between the tooth 34 and the tooth 1), but the tooth 10 and the tooth 34 are deviated. Accordingly, the angles between three teeth to be set to measure the angle are normally 30 deg. from C1 to C12, however, those of C1 and C10 are large, and those of C2 and C9 are small. The passing time of respective angles between tooth are calculated on the basis of the generating intervals of signals of a crank position sensor 400 after fuel is cut and an engine is twice or more rotated. The value is compared with the theoretical time (not constant because the crank shaft is not uniformly rotated) of passage of respective tooth, corresponding to the rotational speed at that time, the deviation time is calculated, and the deviation amount of the angles between tooth are calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a crank angle detecting device for an internal combustion engine.

[0002]

2. Description of the Related Art In controlling an internal combustion engine, in order to inject fuel at a predetermined injection timing, to ignite at a predetermined ignition timing, or to detect misfire,
It is important to detect the crank angle. This is, in fact, a certain crank angle, for example 30 ° C.
In many cases, the time required to pass through A is measured, and the measurement is performed based on the measured value.

[0003] This is performed, for example, as follows.
The rotor rotating in conjunction with the crankshaft is provided with 36 teeth evenly arranged at every 10 °, and these teeth pass through the fixedly arranged electromagnetic pickup side, and generate a signal every time the teeth pass. To do. Then, since the electromagnetic pickup generates a signal for each tooth, a signal is generated for every 10 ° CA. Therefore, every third interval of this signal is measured.

[0004]

However, since these teeth are formed by machining, they are not arranged evenly with errors (tooth deviation). Therefore, there are places where the distance between teeth is long and places where it is short. Where the distance between the teeth is long, the signal generation interval becomes long, and if it is considered correct, it is determined that the rotation speed is low because the time required for passage is long, and conversely, If the interval is short, the signal generation interval becomes short, and if it is considered to be correct, it may be determined that the rotation speed is high because the time required for passing is short. If there is such an error, highly accurate control cannot be performed.For example, when misfire is determined, misfire is determined without misfire, or conversely, misfire is not misfired. Is determined.

[0005] Japanese Patent Application Laid-Open No. Hei 8-
Although there is a device disclosed in Japanese Patent No. 28338, this device corrects the position of the top dead center using an in-cylinder pressure sensor, and does not solve the above-described problem of the crank angle detecting device. The present invention has been made in view of the above circumstances, and has as its object to provide a crank angle detection device that is not affected by manufacturing errors.

[0006]

According to the first aspect of the present invention, there is provided a rotor which rotates in conjunction with a crankshaft of an engine and has a plurality of objects to be detected arranged at predetermined target intervals in a circumferential direction. A signal generating means fixedly disposed at a position where the detected objects of the rotor pass close to each other, and generating a signal each time each of the detected objects passes; and a signal generating means when a predetermined detected object has passed. From the timing at which the signal is generated and the timing at which the signal generating means generates a signal when another predetermined detected object passes, a predetermined inter-detected object actual distance that calculates an actual crank angle between the detected objects is calculated. A crank angle calculating means for calculating a target value of a crank angle between the detected objects used for calculating the crank angle by the crank angle calculating means based on a target interval between the detected objects; Degree calculating means, an actual crank angle between the predetermined detected objects calculated by the predetermined inter-subject actual crank angle calculating means, and the predetermined detected object calculated by the predetermined inter-subject target crank angle calculating means. A target crank angle between the bodies, and a deviation amount calculating means for calculating a deviation amount from a target value of the distance between the detected objects from a difference between the target crank angle and the deviation amount calculating means when the engine is in a non-combustion state. And a crank angle detecting device for calculating the deviation amount.

[0007] In the crank angle detecting device constructed as described above, the amount of deviation of the actual value of the crank angle between the crankshaft of the engine and the detected object arranged on the rotor rotating in conjunction with the target value from the target value is calculated. You.

According to a second aspect of the present invention, in the first aspect of the invention, the internal combustion engine includes a fuel cut device, and after a predetermined period of time has elapsed since the fuel cut device started cutting the fuel. The present invention provides a crank angle detection device adapted to calculate a shift amount. In the crank angle detecting device configured as described above, the deviation amount is calculated after a predetermined period of time has elapsed since the fuel cut device started cutting the fuel, so that the calculation accuracy is high.

According to a third aspect of the present invention, there is provided a crank angle detecting device according to the first aspect of the invention, wherein the calculated deviation amount is used for correcting a crank angle used for controlling the engine. . With this configuration, the crank angle used for controlling the engine is corrected by the deviation calculated by the crank angle detecting device configured as described above, and the accuracy of controlling the engine is improved.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the shift amount is calculated for two adjacent two or more predetermined detection objects, and each of the calculated shift amounts is calculated. A crank angle detection means for correcting a shift angle so as to correct each shift amount such that a total integrated value of the shift amount falls within a predetermined range, and correcting a crank angle based on the corrected shift amount. An apparatus is provided. In the crank angle detection device configured as described above, the integrated value of the shift amount can be set to 0 (zero), and the accuracy of correcting the crank angle is improved.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing the configuration of the present invention. The engine 100 is a four-cylinder engine, and a rotor 200 for measuring a crank angle and a crank timing pulley 300 for driving a camshaft (not shown) are fixed to a crankshaft 110.
The crank timing pulley 300 drives a camshaft (not shown) at a rotation ratio of 1/2 via a timing belt (not shown). The crankshaft 110 rotates clockwise in the figure as shown by the arrow.

Although the rotor 200 is provided with teeth arranged at a target interval of 10 degrees, the total number of teeth is 34 because there is a missing tooth portion A. The first tooth after the missing tooth portion A is set to 1, the next tooth is set to 2 when viewed counterclockwise from there, and the teeth are numbered in order. Therefore, the number of teeth before the toothless portion A is 34. The crank position sensor 400 includes an electromagnetic pickup and generates a high voltage when the protrusion of each tooth of the rotor 200 passes, and generates a low voltage when the base passes.

An electronic control unit (ECU) 500 is connected to an input interface 510, a central processing unit (CPU) 520, a random access memory (RAM) 530, and a read only memory (ROM) 53.
The present invention is a digital computer comprising 0s, and in the present invention, receives a signal from the crank position sensor 400 and performs an operation described later.

FIG. 1 shows that the projection of the seventh tooth 7 counting from the position following the toothless portion A passes through the center of the crank position sensor 400. At this time, the piston of the # 1 cylinder (shown in FIG. Zu) is just set to become the top dead center. The missing tooth portion A is for specifying the top dead center position as described above.

FIG. 2 is an enlarged view of the rotor 200.
In FIG. 2, every three teeth (only one tooth between tooth 34 and tooth 1)
Is marked with a separator line. These lines indicate the reference position of each tooth for which the transit time is calculated. Each tooth 1 to 3
4 are completely evenly arranged, the inter-dental angles (the angles between the reference positions) C1 to C12 are equal. However, in this embodiment, of the 34 teeth, 32 are evenly arranged, but the teeth 10 are formed shifted toward the teeth 11 and the teeth 34 are shifted toward the teeth 33. It is formed. As a result, C3 to C8, C11, and C12 are equal, but CI and C10 are long, and C3 and C9 are short.

FIG. 3 shows an output waveform of the crank position sensor 400 when the crankshaft rotates completely uniformly. The number below each output waveform is the number of the tooth that output that waveform. The corresponding output waveform is also shifted by the tooth 10 being formed shifted toward the tooth 11 and the tooth 34 being formed shifted toward the tooth 33. FIG. 4 shows a point at which each output waveform of FIG. 3 passes a predetermined reference value (for example, when the output waveform undulates positively and negatively at zero,
(A point passing through zero at the falling edge).

The transit time measures a corresponding rising section of the shaped wave. The time from the rise of the shaped wave corresponding to the output waveform of the tooth 7 to the rise of the shaped wave corresponding to the output waveform of the tooth 10 is S1, and hereafter, assuming S2 to S12, respectively, the crankshaft 110
Are completely evenly rotated, S3 to S8 are equal, but S1 and S10 are long and S2 and S9 are short.

However, the crankshaft 110 is not rotating at a completely uniform speed. Even when the engine 100 is not ignited, the rotation speed of the crankshaft 110 is low when the piston passes through the top dead center,
It is faster in the middle. When ignited, this difference is further complicated by an explosion, indicating a more complex change.

FIG. 5 is a diagram showing the measured transit time of each of the three teeth sections similar to FIG. 2 when the engine 100 is not ignited. This indicates a case where there is no tooth, and a black circle indicates a case where there is a tooth gap as shown in FIG. 5, each value indicated by T30 _i represents the following values. T30 ₁ : transit time between tooth 7 and tooth 10 T30 ₂ : transit time between tooth 10 and tooth 13 T30 ₃ : transit time between tooth 13 and tooth 16 T30 ₄ : between tooth 16 and tooth 19 transit time T30 _5: transit time between the teeth 19 and the teeth 22 T30 _6: transit time between the teeth 22 and the teeth 25 T30 _7: teeth 25 and the transit time between the teeth 28 T30 _8: teeth 28 and teeth 31 T30 ₉ : Transit time between teeth 31 and 34 T30 ₁₀ : Transit time between teeth 34 and 1 T30 ₁₁ : Transit time between teeth 1 and 4 T30 ₁₂ : Teeth 4 and teeth Transit time between 7

Next, the calculation of tooth misalignment according to the invention, the calculated correction of T30 _i with teeth shift will be described. First, in the engine 100 combustion state, as described above, the variation of the rotational speed of the crank shaft 110 is complicated, the correction calculation based on the T30 _i when the engine 100 is in a non-combustion state. Here, since the engine 100 is in a non-combustion state during traveling when the fuel is cut, the engine 100 is configured to perform a fuel cut. The fuel adhering to the wall of (z) may flow into the combustion chamber and burn,
The correction calculation is performed after rotating more than a predetermined number of times (in this case, for example, after rotating more than twice).

Hereinafter, the calculation of the correction will be described with reference to the flowchart shown in FIG. Step 601 is a step of calculating the passage time of each T30 _i , that is, the passing time of three teeth (the missing tooth part is one tooth). This measures the transit time at each of the inter-tooth teeth angles C1 to C12 in FIG. 2 at the intervals of the shaped waves as shown in FIG. Step 602 is a step of calculating a correction value T30K _i according to the invention of T30 _i, from T30 _i, value or by converting the learning value KGC30 _i shift angle _{time, KGC30 i × (T360 i /} 3
60) is subtracted. Here, T360 _i is a time required for the rotation of the crank angle of 360 degrees, just before T30
Is a value obtained by integrating the _{1 ~T30 12.} When the deviation angle learning value KGC30 _i is 0 (zero), T30K _i is T
30 _i .

Step 603 is a step for judging whether or not two or more rotations have been made since the start of the fuel cut.
Here, if a negative determination is made, the process ends. If an affirmative determination, and performs a calculation for updating the learning value KGC30 _i of the shift angle in step 604, 605. First, in step 604, the correction value T30K _i up to the previous by subtracting the theoretical value T30R _i of the interval, determining the time difference DLT30R _i between the theoretical time of the section. Here, the theoretical T30R _i values corresponding to each rotational speed is stored in the ROM540 of ECU500 been mapped as shown in FIG.

Next, at step 605, the time difference DLT30R _{i from the} theoretical time is multiplied by 360 / T360 _i to calculate the deviation angle DLKG from the theoretical angle, that is, 30 degrees.
In terms of the C30 _i. Then, the deviation angle DLKGC30 _i was stopped even step 605 in step 606,
A value obtained by dividing by a predetermined number of times of smoothing n, that is, DL
KGC30 _i / n is the learning value KGC3 of the deviation angle up to the previous time.
Is added to the 0 _i, new, of the deviation angle learning value KGC30 _i
To end. Here, the reason for dividing by the number of times of smoothing n is to avoid a sudden change. If, for example, 8 is used as the number n of times of annealing, by repeating eight times, the value is corrected to a value that matches the theoretical value.

In the above calculation, the deviation DLKGC30
_Although the integrated value of _i should be 0 (zero), it may not be 0 (zero) due to each calculation. Therefore, the routine shown in the flowchart of FIG. 8 is executed so that the integrated value becomes zero. This routine is executed between steps 605 and 606 in FIG. The basic idea is that a value SUMDL1 obtained by integrating only positive values of the DLKGC30 _i and a value SUMDL obtained by integrating only negative values
C2 is determined respectively. Further, the sum DLSUM is obtained.

Then, each positive DLKGC 30 _{i is set} to DLS
Correct the value obtained by multiplying the contribution rate to SUMDLC1 of DLKGC30 _i to half the value of the UM, the respective negative DLKGC30
_i to half the value of DLSUM, the SUM of DLKGC30 _i
The correction is made by multiplying the contribution ratio to DLC2.

FIG. 8 is a flowchart of the routine. Steps 801 to 803 reset i to 1 when the TDC (top dead center) of the # 1 cylinder is reached, and execute SUMDLC
This is a step for resetting 1 and SUMDLC2 to 0 to start this routine. Then, in step 804, the sign of the DLKGC _i is determined. If the sign is positive, only the positive DLKGC _i is integrated in step 805. If the sign is negative, the negative DLKC _i is calculated in step 806.
Only GC _i is integrated. In the next step 807, i is incremented (increased by 1), and in step 808,
If i is 12 or less, the process returns to step 804. Thus, twelve DLKGC _i, respectively, the positive is accumulated positive only, negative are accumulated negative only. Then, 12 pieces of step 809 of the DLKGC _i,
SUMDLC1 that integrates only positive and SU that integrates only negative
The sum DLSUM of MDLC2 is obtained.

In steps 810 to 815,
Each DLKGC_iAbout DLKGC _iThe positive or negative judgment of
Here, in the case of positive, each DLKGC_iTo step 80
Against SUMDLC1 in half of DLSUM found in 9
DLKGC_iSubtract the product of the percentages of
If each DLKGC_iDL from step 809
DLKGC for SUMDLC2 in half of SUM_iof
Subtract the percentage multiplied.

For example, for i = 1 to 12, step 8
It is assumed that each value of DLKGC _i for determining the positive or negative in 04 is as follows. DLKGC ₁ = 2, DLKGC ₂ = -2, DLKGC ₃ = 0 DLKGC ₄ = 0, DLKGC ₅ = -3, DLKGC ₆ = 4 DLKGC ₇ = 0, DLKGC ₈ = 0, DLKGC ₉ = 1, DLKGC ₁₀ -1 DLKGC ₁₁ = 1, DLKGC ₁₂ = 0

Then, on the positive side, DLKGC ₁
= 2, DLKGC ₆ = 4, DLKGC ₉ = 1, DLKG
Since C ₁₁ = 1, SUMDLC1 = 2 + 4 + 1 + 1 =
8 On the negative side are DLKGC ₂ = −2, D
Since LKGC ₅ = −3 and DLKGC ₁₀ = −1, SU
MDLC2 = (− 2) + (− 3) + (− 1) = − 6. Therefore, DLSUM = SUMDLC1 + SUM
DLC2 = 8 + (− 6) = 2.

[0030] Thus, each value of DLKGC _i corrected in step 812 is as follows. DLKGC ₁ = 2- (2/2) × (2/8) = 2-0.
25 = 1.750 DLKGC ₂ = −2− (2/2) × (−2 / −6) = −
2 + 0.333 = -2.333 DLKGC ₃ = 0- (2/2) × (0/8) = 0 DLKGC ₄ = 0- (2/2) × (0/8) = 0 DLKGC ₅ = −3 (2/2) × (−3 / −6) = −
3-0.500 = -3.500 DLKGC ₆ = 4- (2/2) × (4/8) = 4-0.
5 = 3.500 DLKGC ₇ = 0− (2/2) × (0/8) = 0 DLKGC ₈ = 0− (2/2) × (0/8) = 0 DLKGC ₉ = 1− (2/2) ) × (1/8) = 1-0.
125 = 0.875 DLKGC ₁₀ = −1− (2/2) × (−1 / −6) = −
1-0.167 = −1.167 DLKGC ₁₁ = 1− (2/2) × (1/8) = 1−0.
125 = 0.875 DLKGC ₁₂ = 0− (2/2) × (0/8) = 0

As described above, since the total integrated value DLSUM in step 809 was on the positive side, the positive side DLKGC
_i is modified so that each positive value decreases, and DL on the negative side
KGC _i is modified such that each negative value increases.
Then, when the total integrated value DLSUM is calculated as described below, it becomes 0 (zero). Positive integrated value SUMDLC1 = 1.750 + 3.500
+ 0.875 + 0.875 = 7, integrated value SUMDLC2 on the negative side = −2.333 + (− 3.
500) + (− 1.167) = − 7, total integrated value DLSUM = SUMDLC1 + SUMDLC2
= 7 + (-7) = 0

[0032]

According to the present invention, a crank angle detecting device which is not affected by manufacturing errors is provided, and the tolerance of manufacturing variations of the detected object is increased, thereby improving the productivity. Further, the detection accuracy of the rotation fluctuation can be improved, and the range of detection based on the rotation fluctuation, for example, misfire detection can be increased. In particular, according to the third aspect, the crank angle used for controlling the engine is corrected, and the control accuracy of the engine is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an enlarged view of a rotor.

FIG. 3 is an output waveform of the crank position sensor of FIG. 1 when the crankshaft rotates at a completely uniform speed.

FIG. 4 is a shaped wave obtained by shaping the output waveform of FIG. 3;

FIG. 5 is a diagram illustrating the passage time of each section of L1 to L12 in FIG. 2 in consideration of the actual rotation fluctuation of the crankshaft.

FIG. 6 is a flowchart of a routine for correcting the passage time of each 30 ° CA.

FIG. 7 is a theoretical value of the time required to pass each 30 ° CA.

FIG. 8 is a flowchart of a routine for correcting a shift angle.

FIG. 9 is a flowchart of a routine for correcting a shift angle.

[Explanation of symbols]

 1-34 ... teeth of the rotor 100 ... engine 110 ... crankshaft 200 ... rotor 300 ... crank timing pulley 400 ... crank position sensor 500 ... ECU

Claims (4)

[Claims] 1. A rotor that rotates in conjunction with a crankshaft of an engine, the rotor having a plurality of detected objects arranged at predetermined target intervals in a circumferential direction, and the detected objects of the rotor pass close to each other. A signal generation unit that is fixedly arranged at a position and generates a signal each time each of the detected objects passes; and a timing at which the signal generating unit generates a signal when the predetermined detected object passes, and another predetermined time. A predetermined actual inter-detector actual crank angle calculating means for calculating an actual crank angle between the detected objects from a timing at which the signal generating means generates a signal when the detected object passes; A target crank angle calculating means for calculating a target crank angle between the detected objects used in the calculation based on the target interval between the detected objects; Difference between the actual crank angle between the predetermined detected objects calculated by the cut angle calculating means and the target crank angle between the predetermined detected objects calculated by the predetermined inter-detected target crank angle calculating means. And a shift amount calculating means for calculating a shift amount of the interval between the detected objects from a target value, wherein the shift amount calculating means executes the calculation of the shift amount when the engine is in a non-combustion state. Characteristic crank angle detection device. 2. The system according to claim 1, wherein the internal combustion engine includes a fuel cut device, and the shift amount is calculated after a predetermined time has elapsed since the fuel cut device started cutting the fuel. 5. The crank angle detection device according to 1. 3. The crank angle detecting device according to claim 1, wherein the calculated deviation amount is used for correcting a crank angle used for controlling the engine. 4. The method according to claim 1, further comprising the step of calculating the amount of deviation for each of two adjacent objects to be detected, so that a total integrated value of the calculated amounts of deviation is within a predetermined range. Has a shift amount correcting means for correcting each shift amount,
The crank angle detection device according to claim 3, wherein the crank angle is corrected based on the corrected shift amount.